Plunger type glass feeding apparatus



Aug. 17, 1965 F. J. WYTHE 3,201,218

PLUNGER TYPE GLASS FEEDING APPARATUS Filed Dec. 27. 1961 H al I 72 I 0 lW70 I H:

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EXHAUST PRESSURE M INVENTOR. FREDERICK J. WYTHE BYJ;@,%M 074W EXHAUSTATTORNEYS plunger and wherein the force of feeding apparatus to whichthe "plied includes a vertically reciprocable bracket for sup- UnitedStates Patent 3,201,218 PLUNGER TYPE GLASS FEEDING APPARATUS FrederickJ. Wythe, Hebron, Conn., assignor to Emhart Corporation, a corporationof Connecticut Filed Dec. 27, 1961, Ser. No. 162,335 3 Claims. (Cl.65-330) I feeding mechanism of the type wherein a rotating cam, a

cam follower and a lever linkage are used to lift the gravity is reliedupon for the downward movement of the plunger, a fluid motor forassisting both movements of the plunger so as to provide better controlof the plunger force and to assure positive cam and cam follower contactat all times.

As will be described in more detail hereinafter, the glass presentinvention is apporting the plunger. The bracket is mounted on avertically reciprocable post which is moved upwardly by a 1 lever whenthe lever is pivoted by a cam follower engaging the bottom side of arotating driven cam. A glass feeding apparatus of this type is shown inUS. Patent No. 2,654,184 and in US Patent No. 2,749,665, and it will beseen from these patents that the Weight or gravity force of the plunger,bracket, post, etc. is relied upon to effect the downward movement ofthe plunger.

It is particularly desirable to assist plunger movement in the downwarddirection to overcome the resistance of partially cooled but nonethelessmolten glass. To this 'end, a fluid motor comprising a cylinder andpiston is mounted on a non-moving part of the apparatus with its pistonrod connected to the lever to assist in plunger movement. The fluidmotor is preferably reversible and it is controlled by a two-positionvalve. The valve has .a rack formed thereon which is engaged by a pinionformed on one end of a shaft whose rotation is retarded by a slipclutch. The preferred form of slip clutch comprises a magnetichysteresis brake operable within a housing which is mounted on thebracket for vertical movement. During initial bracket and plungermovement in either direction, there will be no relative movement of thepinion and rack because of the retarded shaft and thus the valve will beshifted to one of its two positions. After the valve has reached thelimit of its movement and is placed in one of its two positions, thebrake or clutch will slip to permit relative rack and pinion movement.

Therefore, the fluid motor is reversed to assist in plunger and bracketmovements in either direction respon- FIG. 1 is an elevational view of aportion of the glass feeding apparatus and it shows all of the elementsthereof that have heretofore been mentioned; and

FIG. 2 is a schematic cross-sectional view showing the clutch andcontrol valve structures.

As shown in FIG. 1 and as more fully shown and described in U.S. Patent2,749,665, the plunger 10. is

mounted on one end of an arm 12 which is adjustably supported on abracket 14 for vertical reciprocation therewith relative to a bowl 16.The bowl 16 is a receptacle for molten glass which is dischargedtherefrom through a bottom opening 18 in the bowl, the said openingbeing defined by an orifice ring 20. The glass is discharged as a resultof the vertical reciprocation of the plunger 10 over the opening 18 andsubstantially along the vertical axis thereof.

The plunger is connected to the end of the arm 12 by clamping meansindicated generally by the reference numeral 22, this forming no part ofthe present invention and being shown and described in Patent 2,749,665.The bracket 14, the arm 12 and the plunger 10 are verticallyreciprocated as a result of vertical reciprocation of a shaft or post 24to which the bracket 14 is rigidly connected. The post 24 is movedupwardly and downwardly through upper and lower bushings 26 and 28 whichare a part of the fixed frame of the apparatus, the said frame beingdesignated throughout by the letter F.

Mechanical means is employed to lift the post 24 and thus the bracket 14and plunger 10. Accordingly, this means is indirectly connected with theplunger, and as shown in FIG. 1, it includes a cam 30 which is securedto a cam shaft 32 for driven rotation in a counterclockwise direction.The mechanical means for lifting the plunger also includes a camfollower comprising a roller 34 engaging the bottom side of the cam 30,the roller being supported on the end of a pivoted arm 36 and beingfurther supported on a pair of straps which straddle the cam, one of thestraps being designated by the numeral 38. The straps have extensionssuch as shown at 40 which project upwardly and journal a roller 42engaging the upper arcuate surface 44 of a lever 46. The lever 46 ispivotally mounted at 48 to the frame F and the arcuate surface 44thereof is formed on a radius from the center of the cam-followingroller 34 when the said roller is on that portion of the cam peripherynearest the cam axis.

On the opposite side of the pivot point 48 from the arcuate portion 44,the lever 46 has a portion 50 which is bifurcated at its end to straddlethe vertically movable post 24. The said bifurcated end is pivotallyconnected to a pair of linkages, such as the link 52, which arepivotally connected at their other ends to a pin 54 which is securedtransversely in the post 24. Therefore, upon clockwise pivoting movementof the lever 46 as viewed in FIG. 1, the post 24 will be lifted and thislifts the plunger 19 and the bracket 14.

It will be seen that the lever 46 is pivoted in the clock wise directionto lift the plunger when the cam following roller 34 rides upon theradially outer portions of the periphery of the cam 39. The magnitude oflifting movement or stroke of the plunger it) varies in proportion tothe distance separating the axis of the lever actuating roller 42 fromthe lever pivot axis 48. This distance can be adjusted to adjust thestroke by means of a manually operated screw 56 which is threaded intothe support for the lever actuating roller 42.

As has been said, and as will be seen from the drawing, the return ordownward stroke of the plunger 10 is caused primarily by the gravityforce or weight of the plunger, the bracket 14, the post 24 and theassociated vertically movable elements. As has also been said, bothmovements of the plunger 10 are assisted by a fluid 7 motor identifiedby the numeral 58 on the drawing. The

said fluid motor comprises either an hydraulic or pneumatic cylinderwhich is supported on the frame F for substantially vertical movement ofa piston having a rod eX- tension 60 which is pivotally connected withthe lever 46 on the portion 50 thereof. A fluid conduit 62 is connectedto the upper end of the fluid motor cylinder and a similar fluid conduit64 is connected to the lower end of the said cylinder. These conduitsextend from a control valve housing 66 which is mounted on the frame F.As will be described more fully, the control valve functions to connectthe fluid conduit 62 to a source of fluid funder pressure whileexhausing fluid from the conduit sist clockwise movement of the lever 46and lifting movement of the plunger 10.

As shown in both figures of the draWing, the two-position valve 68 whichis operable within the valve housing 66 has a gear rack extension 70formed thereon and which is reciprocated by a slip clutch indicatedgenerally at 72 to place the valve in its one end other positions. Thepreferred slip clutch "12 comprises a magnetic hysteresis brake and itincludes a housing 74 which'is supported on the bracket 14 for verticalmovements therewith. The clutch also includes an armature 76 which iskeyed to a shaft 78 having a pinion 80 formed on its outer end to engagethe rack 70. The clutch or brake is normally energized to retardrotation of the armature 76 and the shaft 78 whereby upon initialmovement of the plunger and bracket and thus the clutch housing 74, theretarded shaft and pinion 80 will not rotate and thus the rack 70 andvalve 68 will be moved responsive to initial movement of the plunger.That is, when the plunger starts to move downwardly thevalve 68 will beplaced in its one position at the limit of its downward movement.Thereafter, the armature 76 will slip and relative movement will takeplace between the pinion 80 and the rack 70. When the plunger 10 startsto move upwardly, the retarded clutch armature and shaft will cause therack and valve 68 to be moved upwardly to the limit of its movementwithin the housing 66, thus placing the valve in the other of its twopositions. Thereafter, continued upward movement of the plunger willcause clutch slippage and there will'be relative rack and pinionmovement.

As will be observed with reference to FIG. 2, when resulting frominitial downward movement of the plunger 10, it will direct fluid underpressure from a source into the conduit 62 to the top of the fluid motor58 to assist in the downward movement and to help maintain the plunger10 in its down position. At the same time, the valve 68 will connect theconduit 64 to an exhaust port. When the valve is in its other or upposition, the conduit 64 will be connected to the pressurized sourcewhile the conduit 62 is exhausted. It will be noted that the valve isconnected to a tension spring 82 tending to place it in its other or upposition. This is so arranged to effect upward movement of the plunger10 or to assist in such upward movement to avoid freeze-up of theplunger in the bowl outlet whenever the glass feeding apparatus is notbeing operated.

In most installations, it is desirable to limit the upward force appliedby the fluid motor 58 to less than the weight of the plunger, thebracket, and the associated vertically movable elements. The purpose forthis is to assure that positive contact will always be maintained, dueto the force of gravity, between the cam follower 34 and the cam 30. Insuch installations, it will be necessary to stop the operation of thefeeder mechanism with a radial distant point on the periphery of the cam30 engaging the follower 34 in order to assure that the plunger 10 willbe elevated.

"the valve 68 is in its one position, i.e., the down position The meanslimiting the upward force of the fluid motor 58 comprises pressurelimiting means in the form of a valve 84 which is disposed in an exhaustconduit 86 tapped into the conduit 64. Thus, whenever the pressure inthe conduit 64 exceeds a predetermined level, the valve 34 will open toreduce the pressure in the conduit 64 to the level wherein the resultantupward force is less than the applied force of gravity.

The invention claimed is:

1. In glass feeding apparatus of the type which includes a bowl having abottom opening for the discharge of molten glass as a result of verticalreciprocation of a plunger over the opening, and wherein plunger liftingis effected primarily by mechanical means connected with the plunger andincluding a rotating cam while downward movement is caused by gravity,improved means for assisting plunger movement in both directions andcomprising a reversible fluid motor connected with the mechanical means,a two position control valve operatively connected with said fluidmotor, and valve actuating means comprising a magnetic clutch having ahousing mounted for movement with the plunger and also having a'retarded shaft provided with a pinion, and the valve being provided witha rack engaged by the pinion whereby during initial downward movement ofthe plunger there is no relative rack and pinion movement so that thevalve is placed in one position to effect a fluid motor assist to suchplunger movement and thereafter the clutch slips to permit relative rackand pinion movement, and

whereby during initial upward movement of the plunger there is norelative rack and pinion movement so that the valve is placed in itsother position to effect a fluid motor assist to such plunger movementand thereafter the clutch slips to permit relative rack and pinionmovement.

2. Improved means for assisting glass feeder plunger movement as setforth in claim 1 and wherein fluid pressure limiting means isoperatively connected with said valve and fluid motor to limit thelifting force provided by the fluid motor to less than the, gravityforce.

3. In glass feeding apparatus of the type which includes a bowl having abottom opening for the discharge of molten glass as a result of verticalmovement of a plunger over the opening; and wherein the plunger issupported on a vertically reciprocable bracket which is lifted by arotating cam, cam follower and lever connected with the bracket whiledownward movement thereof is caused by gravity; improved means forassisting plunger reciprocation in both directions and comprising areversmeans operatively connected with said valve and fluid motor tolimit the lifting force provided by the fluid motor to less than theforce of gravity.

References Cited by the Examiner UNITED STATES PATENTS 2,725,681 12/55Wythe 65-330 2,749,665 6/56 Peiler 65-330 2,902,612 9/59 Whearley 310-2,912,607 11/59 Duncan 310-99 DONALL H. SYLVESTER, Primary Examiner,

1. IN GLASS FEEDING APPARATUS OF THE TYPE WHICH INCLUDES A BOWL HAVING ABOTTOM OPENING FOR THE DISCHARGE OF MOLTEN GLASS AS A RESULT OF VERTICALRECIPROCATION OF A PLUNGER OVER THE OPENING, AND WHEREIN PLUNGER LIFTINGIS EFFECTED PRIMARILY BY MECHANICAL MEANS CONNECTED WITH THE PLUNGER ANDINCLUDING A ROTATING CAM WHILE DOWNWARD MOVEMENT IS CAUSED BY GRAVITY,IMPROVED MEANS FOR ASSISTING PLUNGER MOVEMENT IN BOTH DIRECTIONS ANDCOMPRISING A REVERSIBLE FLUID MOTOR CONNECTED WITH THE MECHANICAL MEANS,A TWO POSITION CONTROL VALVE OPERATIVELY CONNECTED WITH SAID FLUIDMOTOR, AND VALVE ACTUATING MEANS COMPRISING A MAGNETIC CLUTCH HAVING AHOUSING MOUNTED FOR MOVEMENT WITH THE PLUNGER AND ALSO HAVING A RETARDEDSHAFT PROVIDED WITH A PINION, AND THE VALVE BEING PROVIDED WITH A RACKENGAGED BY THE PINION WHEREBY DURING INITIAL DOWNWARD MOVEMENT OF THEPLUNGER THERE IS NOT RELATIVE RACK AND PINION MOVEMENT SO THAT THE VALVEIS PLACED IN ONE POSITION TO EFFECT A FLUID MOTOR ASSIST TO SUCH PLUNGERMOVEMENT AND THEREAFTER THE CLUTCH SLIPS TO PERMIT RELATIVE RACK ANDPINION MOVEMENT, AND WHEREBY DURING INITIAL UPWARD MOVEMENT OF THEPLUNGER THERE IS NO RELATIVE RACK AND PINION MOVEMENT SO THAT THE VALVEIS PLACED IN ITS OTHER POSITION TO EFFECT A FLUID MOTOR ASSIST TO SUCHPLUNGER MOVEMENT AND THEREAFTER THE CLUTCH SLIPS TO PERMIT RELATIVE RACKAND PINION MOVEMENT.